This invention relates to an intake system for a multi-cylinder internal-combustion engine, which intake system is held above the cylinders on the internal-combustion engine and is decoupled from vibrations.
In the German Patent Document DE-36 41 811 C1, an intake system for a multi-cylinder internal-combustion engine is disclosed which is held on the cylinder head, being decoupled from vibrations, by means of elastic bearing elements. In this case, the bearing elements are subjected to compression by means of screwed connections between the intake system and supports on the cylinder head. During mounting, access is difficult to these screwed connections as well as to the connecting points between individual intake pipes of the intake system and inlet ports which are formed in the cylinder head and lead into a flange facing.
It is an object of the invention to develop an intake system in such a manner that a simple and fast mounting on the internal-combustion engine is ensured and, at the same time, the intake system is optimally decoupled from the internal-combustion engine with respect to vibrations.
This object is achieved by providing an arrangement comprising:
a plurality of engine cylinders,
a cylinder head for the engine cylinders,
an intake system for supplying combustion material to the cylinders through the cylinder head,
and a holding arrangement for holding the intake system on the engine with decoupling of the intake system from engine vibrations, said holding arrangement including a first elastic decoupling element that is arranged under tension and serves to isolate the intake system from engine vibrations.
According to a first embodiment of the invention, the arrangement of a decoupling element which operates between the intake system and the cylinder head and is under tension and of another decoupling element which is arranged between the cylinder head and the individual intake pipes of the intake system and is under compression permit a mounting and demounting of the intake system in a few steps. For this purpose, it is only necessary to tighten tension devices which are accessible from above and penetrate the intake system perpendicularly whereby the intake system is decoupled with respect to vibrations by being elastically connected with the internal-combustion engine by way of the decoupling elements supported on the cylinder head. The forces which in this case are transmitted by the tension elements to the intake system are supported on the other decoupling elements which are placed between the cylinder heads and the intake system before the mounting of the intake system.
For the mounting and the demounting of the intake system, it is therefore only necessary to insert the additional decoupling elements before the placing of the intake system; the tightening of the tension device which may, for example, be constructed as a tension bolt, takes place subsequently.
Should accessibility of the additional decoupling element in the case of an in-line internal-combustion engine be difficult, for example, because of the assembling conditions, or should it be completely impossible in the case of a V-engine whose one-piece intake distributor of the intake system completely covers the inlet ports formed in the cylinder heads, this arrangement nevertheless permits a simple and fast mounting.
In an advantageous development of this embodiment of the invention, an intake pipe socket is arranged between the additional decoupling elements, which simultaneously act as a sealing device, and a flange facing. Between adjacent intake pipe sockets, the decoupling elements are supported on the flange facing by way of pipe-type fastening devices. As a result, no additional machined flange facing is required on the cylinder head for the supporting of these pipe-type fastening devices.
In a further development, the individual intake pipe sockets of one cylinder bank leading to each cylinder are constructed together with the pipe-type fastening devices in one piece as a bridge. In the case, for example, of an internal-combustion V-engine comprising four cylinders for each cylinder bank, these bridges are screwed together with the flange facing by means of a pipe-type fastening device arranged between the first and the second as well as by means of one arranged between the third and the fourth intake pipe socket. The decoupling elements are held on arms which are constructed in one piece with the pipe-type fastening devices and extend transversely with respect to the bridge into the direct proximity of the cylinder heads. As a result, the tension bolts can penetrate an exterior area of the intake distributor, such as an air collector, in a simple manner. In order to reach components which are arranged below the intake system in the V of the internal-combustion engine, only four tension bolts must be unscrewed, whereby the intake distributor can be lifted off.
According to a second embodiment of the invention, the intake system is held on the internal-combustion engine by means of dampers which reach around a pot-shaped housing which is detachably connected with the internal-combustion engine. In this housing, a rubber-elastic mass is arranged which is penetrated by a clamping sleeve equipped with a disk arranged on the end face and which is detachably connected with the intake system. This arrangement permits a simple and fast mounting and demounting of the intake system on the internal-combustion engine, while the vibrations are decoupled at the same time by means of the detachable connection between the clamping sleeve and the intake system.
In an advantageous development of this last-mentioned embodiment, the intake system and the clamping sleeves are connected with tension bolts which almost perpendicularly penetrate receiving devices constructed in the intake system. This ensures a good accessibility of the connection. A stop, which is arranged in the receiving device, limits the forces transmitted as a result of the screwed connection from the clamping sleeve to the rubber-elastic mass so that a desired characteristic of the damper can be adjusted.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings.